HIPPOLYTE LANGLOIS (1839— ), French general,, was born at Besancon in 1839, and, after passing through the cole Polytechnique, was appointed to the artillery as sub-lieutenant in 1858, attaining the rank of captain in 1866. He served in the army of Metz in the war of 1870. Eight years later he became major, in 1887 lieutenant-colonel and in 1888 colonel. At this time he was appointed professor of artillery at the Ecole de Guerre, and in this post he devoted himself to working out the tactical principles of the employment of field artillery under the new conditions of armament of which he foresaw the advent. The public re:ait of his work was the great treatise L'Artillerie de campagne (1891—1802), which may still be regarded as the classic of the arm. In 1894 he became general of brigade, and in 1898 general of division. For two years after this he was the commandant of the Ecole de Guerre at the time that the modern French strategical and tactical " doctrine " was being developed and taught. He was, however, regarded as a leader as well as a theorist, and in 1901 he was selected to command the XX. Army Corps on the German frontier, popularly called the " iron " corps. In 1902 he became a member of the Conseil superieur de la Guerre, consisting of senior generals marked out for the higher commands in war. He retired from the active list in 1904 on reaching the age limit, and devoted himself with the greatest energy to critical military literature. In 1907 he began the publication of a monthly journal of military art and history, the Revue militaire generale. The most important of his other works are Enseignements de deux guerres recentes and Consequences tacliques du progres de l'armement.